PostGIS  3.0.0dev-r@@SVN_REVISION@@

◆ cluster_within_distance_garray()

Datum cluster_within_distance_garray ( PG_FUNCTION_ARGS  )

Definition at line 2954 of file postgis/lwgeom_geos.c.

References ARRAY2LWGEOM(), array_nelems_not_null(), cluster_within_distance(), gserialized_from_lwgeom(), linemerge(), LW_SUCCESS, lwgeom_free(), lwgeom_geos_error(), PG_FUNCTION_INFO_V1(), and SRID_UNKNOWN.

Referenced by clusterintersecting_garray(), pgis_abs_out(), and pgis_geometry_clusterwithin_finalfn().

2955 {
2956  Datum* result_array_data;
2957  ArrayType *array, *result;
2958  int is3d = 0;
2959  uint32 nelems, nclusters, i;
2960  LWGEOM** lw_inputs;
2961  LWGEOM** lw_results;
2962  double tolerance;
2963  int srid=SRID_UNKNOWN;
2964 
2965  /* Parameters used to construct a result array */
2966  int16 elmlen;
2967  bool elmbyval;
2968  char elmalign;
2969 
2970  /* Null array, null geometry (should be empty?) */
2971  if (PG_ARGISNULL(0))
2972  PG_RETURN_NULL();
2973 
2974  array = PG_GETARG_ARRAYTYPE_P(0);
2975 
2976  tolerance = PG_GETARG_FLOAT8(1);
2977  if (tolerance < 0)
2978  {
2979  lwpgerror("Tolerance must be a positive number.");
2980  PG_RETURN_NULL();
2981  }
2982 
2983  nelems = array_nelems_not_null(array);
2984 
2985  POSTGIS_DEBUGF(3, "cluster_within_distance_garray: number of non-null elements: %d", nelems);
2986 
2987  if ( nelems == 0 ) PG_RETURN_NULL();
2988 
2989  /* TODO short-circuit for one element? */
2990 
2991  /* Ok, we really need geos now ;) */
2992  initGEOS(lwpgnotice, lwgeom_geos_error);
2993 
2994  lw_inputs = ARRAY2LWGEOM(array, nelems, &is3d, &srid);
2995  if (!lw_inputs)
2996  {
2997  PG_RETURN_NULL();
2998  }
2999 
3000  if (cluster_within_distance(lw_inputs, nelems, tolerance, &lw_results, &nclusters) != LW_SUCCESS)
3001  {
3002  elog(ERROR, "cluster_within: Error performing clustering");
3003  PG_RETURN_NULL();
3004  }
3005  pfree(lw_inputs); /* don't need to destroy items because GeometryCollections have taken ownership */
3006 
3007  if (!lw_results) PG_RETURN_NULL();
3008 
3009  result_array_data = palloc(nclusters * sizeof(Datum));
3010  for (i=0; i<nclusters; ++i)
3011  {
3012  result_array_data[i] = PointerGetDatum(gserialized_from_lwgeom(lw_results[i], NULL));
3013  lwgeom_free(lw_results[i]);
3014  }
3015  pfree(lw_results);
3016 
3017  get_typlenbyvalalign(array->elemtype, &elmlen, &elmbyval, &elmalign);
3018  result = construct_array(result_array_data, nclusters, array->elemtype, elmlen, elmbyval, elmalign);
3019 
3020  if (!result)
3021  {
3022  elog(ERROR, "clusterwithin: Error constructing return-array");
3023  PG_RETURN_NULL();
3024  }
3025 
3026  PG_RETURN_POINTER(result);
3027 }
uint32_t array_nelems_not_null(ArrayType *array)
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1128
#define LW_SUCCESS
Definition: liblwgeom.h:79
int cluster_within_distance(LWGEOM **geoms, uint32_t num_geoms, double tolerance, LWGEOM ***clusterGeoms, uint32_t *num_clusters)
Takes an array of LWGEOM* and constructs an array of LWGEOM*, where each element in the constructed a...
LWGEOM ** ARRAY2LWGEOM(ArrayType *array, uint32_t nelems, int *is3d, int *srid)
void lwgeom_geos_error(const char *fmt,...)
#define SRID_UNKNOWN
Unknown SRID value.
Definition: liblwgeom.h:187
GSERIALIZED * gserialized_from_lwgeom(LWGEOM *geom, size_t *size)
Allocate a new GSERIALIZED from an LWGEOM.
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